Method and apparatus for erecting helical storage vessel



June 26, 1956 D. J. REED 2,751,672

METHOD AND APPARATUS FOR ERECTING HELICAL STORAGE VESSEL Filed March 5, 1953 5' Sheets-Sheet 1 I c 4 ll 7 H J H a a a a f l o a a H .JIHH \n 1M pCmiE i j gd nM /KIM AT TO R N 5Y5.

D. J. REED 2,751,672

METHOD AND APPARATUS FOR ERECTING HELICAL STORAGE VESSEL June 26, 1956 5 Sheets-Sheet 2 Filed March 5, 1953 INVENTOR. Daniel J. Read By $1M 9 M ATTORNEY 5.

D. J. REED 2,751,672

METHOD AND APPARATUS FOR ERECTING HELICAL STORAGE VESSEL June 26, 1956 5 Sheets-Sheet 5 Filed March 5, 1953 INVENTOR. Daniel J. ReecZ firz uwo 9 it @ZM/ ATTOR N 5Y5.

D. J. REED June 26, 1956 METHOD AND APPARATUS FOR ERECTING HELICAL STORAGE VESSEL 5 Sheets-Sheet 4 Filed March 5, 1953 INVENTOR. Daniel J. Reed findzmqAza/v ATTORNEYS.

D. J. REED June 26, 1956 METHOD AND APPARATUS FOR ERECTING HELICAL STORAGE VESSEL Filed March 5, 1953 5 Sheets-Sheet 5 FIGJO.

INVENTOR. Daniel J.Reed BY $1M? AT TOR NEYS.

.volutions.

United States Patent f 2,751,672 i l Patented -J1me 26, 1-956 This inventionrelates ;-tov storage vesselsand.-more-;par-

-.ticular,ly.,to a method. and apparatus .fonerecting.ahelically .mum of jointssand connections.

'Still' another object iszto provide art-apparatus .which will unwindametalsheet from ascoil. andprogressively ,form the. same intoa series of. helicalconvolutions...

A furtherobject is to. provide anerecting apparatus which. has sufiicient strength to supportthe entire silo and .yetconsists of a small-number ofzlightweighgpieces which may be readily assembledand packedvfor ship- .mentto. various erecting locations in thefield.

Another object .is to provide. a. method. of.- erecting -..a

.silowh-ich will. substantially reduce the amount of-bot-h manual and mechanical handling ofthe material.

.The ordinarymetalstorage vessel. or silo is. constructed .fromv a. number of rectangular steel plates whichaare .in- .dividually squared, drilled, rolled to curvatureandcoated.

Both in the field and in the shop a largeproportibn Qfzthe total labor is spent in the repeated. handling of the.- multiple;parts.

Ihis-inetficiency may be overcome by employing a helical-wound. silow of the typev described. in the copending .applieation of .Erwin-G..-Dueringer SerialNo. 3.3.7,,1Q'1, .filedEebruary 1.9, .1953, entitled, ,Storage Vessel andlassigned to a common assignee. This :silo.-: comprises.-a

cylindrical. body portion formedof va. numberof. sheets which are. helically wound in aseries. of. overlappingeon- The trailing end of each-sheetvis.boltcd..to the leadingend of thesfollowing sheet, andthelower edge of each convolutionis. bolted to the lpller. edge; of-the following convolution to provide an integral substantially The present, invention is. directed to. amethod and, ap-

paratus. for theerection of this helical silo ..and. consists of a helical track carriedby .asupporting.sflucturewhich .rests on the. silo foundation. The top .sheet, .in coiled orm,.. is. disposed .on. a reel. or..-turntable. adjacent. the; supportinglstructure, and, a.;plurality ofsheet. carriers which ..are. adapted to. rideconzthe. track, engage the...sheet.v The sheet carriers are moved. upwardly .on. the :track by .a hydnaulidcylinder causing, the. sheet-.10 pnogressively v11nwind .from the .coil and form into a .series..of helical .convolutions.

After. the top sheet has been .helieally wound. the remaining coiled sheets are successively: disposedon the reel. and. progressively wound into. helical form. The lower edge vof each, helical -convolutionis bolted or otherwise secured .to the upper edge of, the

following convolution as each convolution is completed.

A' vertical support disposed contrall'y of the supporting S tune-supponts;.theroof member and when the body portionthasbeen wound to: a sufficient height. thev roof is ,attachedr-thereto.

Afitertheentire bod-yportion has thusbeen completed,

ithe structure; is.backed.downwardly on thehelical track,

with the hydraulic cylinder serving to lirnit the speedsof the movement, until. the structure restsv on-the-foundation.

in. the. drawings:

.F gure 1. islaperspectiveview of the completed helically wound silo;

Fig- 2 is. .an -enlarzged. fragmentary perspective view of thelower. portion of thesilo, with parts broken. away and s tion d;

Big, 3 is a fragmentary vertical sectionshowing the attachmentofthe body portion of .the. silo to the foundation;

Fig. 4,.is a perspective. .view showing. :the..a .sse m;bly of the. track, ,the ,radial supports andthe center .post;

5. is. a. detail perspective view showing a track support unitanclitsattachmentto.. the.base ring;

Fig. 6is a perspective view of the turntable employed to support thecoiledsheets;

Fig. 7 .is a perspective view showing the use .of sheet hangersv in initially unwinding .theluppermost. coiled shee .Ei'g. .8 is a perspective. view- .sho.wing. .the. coiled sheets being wound in a helical manner and the attacbment of .theroof toithe uppermostconvolution;

QEig, 9 .isaperspective view showing .ae sheetcarrier mountedont-he track. and ahydraulic foradvancing the sheet carrier; and

10 is a longitudinal. seetionrof. a. sheet carrier mounted onthe track.

Referring: to the. drawings. there is shown. an. apparatus .iior. theerectionofa. silo 1 substantiallvdeseribed in copending application Serial No. 337,7Ql,. filed February 19, 1953,. andentitled, .Storage. Vessell Ihesilo as. shown in the .drawingsh cornprises a gen- .erally cylindrical. body portion whichis enclosed at the .lop. by va. roof member 2- and supported beneath grade .level by an annular .footingv 3..

The body portion of silo 1 is-formedpfa numbenof .metal sheets 4. which are twoundin aseries of helical con- .volutions. coated. with glass p lastic or thelike.

To withstand corrosion, the vsheets Amay be The. trailing end of eachsheet 4 isboltedtosthe leading end of the following sheet and the lower.edge;pm

tionofleach' convolution is.similarly.secured-bygbolts to .theupper :edge portion. of the following convolution'to providethe. integral body portion of ;the silo.

surfaceofsilo 1 approximately atgrade level-and carries .unloadertrough .9. A suitable conveyor unit:,.not .shown,

may be disposed within trough 9 and serves to convey ,Ihecut silagewithin. tr.o.ugh:9 .to therexterior oisilo. .Silo .1 is. provided with .a manway 10 which registers .with trough .9 and serves as an exit. forthe removal of the cut: silage.

A skirt ring ll is inwardly- :spaced from silo ;1-..an d

extends.-Htflfownwardly from track 8 to footing 3. Ring I1 serves asa form for-concrete supporting.wall-l2ywhich is. poured .into the: annular space between .silo- 1 and ring-11.

The apparatus for. the erection. of .silo ;1;eomprises, ingeneral, a. supporting .fixture 13. which ,rests. on footing H3 .andscarriesa generally helical track 1,4. A turntable 15'is disposed adjacent the fixture ll on grade level. and serves. to rotatably support the coiled sheetsA. A number of sheet carriers 16 removably engage the upper edge portion of the free end of sheets 4 and are adapted to move on track 14 to progressively unwind the coiled sheets 4 and form the same into a series of helical convolutions.

Fixture 13 includes a base angle ring 17 which rests 'on footing 3 inside and adjacent the radius on which anchor bolts 7 are located. For ease of handling ring 17 may be formed of a number of arcuate segments each of which has a. vertically disposed socket member 18 secured to the horizontal flange thereof. Adjacent segments of ring 17 are secured together by means of splice plate 19 to form the completed ring 17. 'The ring 17 may be temporarily secured in proper position by means of clamps 5, as shown in Fig. 4.

T he track 14 is carried by a plurality of circularly spaced vertical track supports 20, as shown in Figs. 4 and 5, which include an outer supporting member 21 and an inner elbow supporting member 22 which is attached to the lower portion of outer member 21.

The lower end of each outer member 21 is adapted to telescope within the respective vertical cup member 18 and is locked therein by pin 23. The length of each vertical support 20 is progressively increased toenable track 14, which is carried by the supports 20, to be in the shape of an ascending helix.

Added rigidity and strength is provided for each support 20 by a pair of horizontal braces 24 which serve "to join outer member 21 and inner elbow member 22. Suitable scaffold boards may be disposed across braces 24 to facilitate movement on the fixture 13 by the erection crew.

The upper end of outer member 21 carries an outer rail supporting bracket 25 while the upper end of elbow member 22 carries a vertically disposed inner rail supporting bracket 26. Each of the supporting members 21 and 22 carries a pair of diagonal braces 27 which are pivotally secured at their lower extremities between a pair of brackets 28. Brackets 28 are welded to the respective members 21 and 22. The hinged attachment of diagonal braces 27 affords space saving for packing and shipment.

The helical track 14 is carried by vertical supports 20 of fixture 13 and comprises an outer rail 29 and an inner rail 30. Rails 29 and 30 are each constructed of an angle bar curved to the shape of a true helix. Outer 'rail 29 is provided with upwardly and inwardly extending flanges while the inner rail 30 has downwardly and outwardly extending flanges. 29 and 30 may be formed of a number of arcuate segments which are bolted together by means of splice plates 31 to form the rail.

The inwardly extending flange of outer rail 29 is bolted to-the respective brackets 25, and additional support is given to rail 29 by the attachment of the free upper ends of diagonal braces 27 to suitable lugs disposed on the under surface of rail 29 intermediate the position of attachment of brackets 25 thereto.

by suitable bolts while the outer end thereof telescopes,

For ease of handling rails 3 The downwardly extending flange of inner rail 30 is bolted to the respective brackets 26, and the free ends of diagonal braces 27 are secured to the vertical flange 'of rail 30 by bolts.

The upper end of post 32 carries an umbrella-like support formed of an upper supporting ring 34 and aplurality of radially extending braces 35 which connect ring I 34 to the post 32. Roof 2 of silo 1 is adapted to rest -on ring 34 during erection of the silo. k- Added rigidity' is given to fixture 13 by radial supports 36 which serve to connect each vertical support '20 to center post 32.

Each of the radialsupports includes a central brace and is removably secured-to, a tubular connection 38 which is attached to the central portion of the respective inner supporting members 22.

The attachments of the various central braces 37 to post 32 are positioned in the shape of a helix or spiral on post 32 to take-into account the ascending helical contour of track 14.

Each radial support 36 is also provided with a pair of tubular braces 39. The inner end of each brace 39 is pivotally attached to brackets 40 which are welded to central brace 37. The outer or free ends of the upper braces 39 are removably secured by bolts to the brackets 26 attached to the upper extremity of elbow member 22 while the free ends of the lower braces 39 are removably secured between lugs 41 which are attached to the lower portion of members 22.

Sheet carriers 16 are adapted to ride on track 14 and successively engage and support the coiled sheets 4 and wind the same into helical form as the carriers move upwardly on the track. Each of the sheet carriers 16 includes a generally cylindrical body 42 which receives a plunger 43. The end of plunger 43 which is disposed within body 42 is reduced in diameter, and a spring 44 encircles the reduced portion of plunger 43. Spring 44 is interposed between the head of a stud 45 which is disposed within body 42 and the shoulder of plunger 43 to bias the plunger toward inner rail 30.

The exposed end of plunger 43 is bifurcated, anda horizontally disposed roller 46 is rotatably secured between the bifurcated arms of plunger 43 by bolt 47. Roller 46 rides on inner rail 30 and is provided with a circumferential groove which receives the outwardly extending flange of the rail 30.

The outer end of stud 45 projects outwardly from body 42 and extends through suitable openings in a pair of spaced roller brackets 48. A pair Uf rollers 49 are ro tatably secured between the brackets 48.

Rollers 49 are vertically disposed and adapted to ride on outer rail 29. To prevent transverse slippage, rollers 49 are provided with circumferential grooves which receive the upper edge of rail 29.

The outer portion of sheet carrier 16 is prevented from lifting upwardly from rail 29 by a depending hook 50 which is secured to the inner side of outer bracket member 48 and extends downwardly therefrom. The lower portion of hook 50 is bent inwardly around rail 29, but out of contact therewith, and serves to maintain engagement of roller 49 with rail 29.

The outer end, of stud 45 is adapted to engage a bolt hole in the upper edge portion of a sheet 4 and in cooperation with other studs serves to support the sheet as it is advanced and wound into helical form.

To limit the movement of plunger 43 within body 42, the plunger, as seen in Fig. 10, is provided with an outwardly extending pin 51 which moves within a slot 52 in body 42. When roller 46 is out of engagement with rail 30, plunger 43 is urged outwardly by spring 44 and pin 51 moves within slot 52 and strikes body 42 thereby stopping the outward movement of plunger 52 and pre venting removal of plunger 43 from body 42.

To lock plunger 43 in a retracted position so as to facilitate the insertion of the sheet carrier 16 on the track 14, plunger 43 is provided with a recess 53 which receives a spring loaded locking pin 54 when the plunger is retracted to a predetermined position. Pin 54, normally biased inwardly by a suitable spring,-extends indetermined position, pin 54 engages recess 53 to lock the plunger in this retracted position.

v fA hydraulic ;cylinder '55, as shown schematically in Fig. 9, is employed to move the sheet carriers 16 on track 14. "Cylinder 55 is "secured to 'outer' rail'f29 ataposition about one-quarter of a. revolution fromthedowend of 'traclc 14. An oil 'reservoiriand suitable operating"mech- "'anism ffor actuating cyIinderSSis indi'cate'dgenera'lly by 56.

"To permit cylinder 55' to pivot *as the" cylinder drives the carriers 16 along the helical track'14,the lower end 'oficylin'der 55 is"pivotally'fattached' to' the'inwai'dfiange "ofrouter'raill29; as indicated by 57.

Cylinder-"55 is normallyfbiased toward 'outer rail 29 by a"leafspring58which 'is secure dto*rail"2"9. A ,piston rod"'59-'extends*rfrom the upper forward end or t'hecylinder 55 and ant-shaped block-'6t)"is securedtothe working en'ddf the ,piston'rod? 59. Afee'der pawl"61= is' pivotally attached "to the outer extremity o'fblock- 6'0. *P'awl '61 --is' adapted to engage'thebo'dy 42' -of sheet carriers 16 and movesthe' carrier upwardly"on"trac'k '14 aspiston rod- 59 A 'is'extended.

Piston rod59 is' guided' in "reciprocalmovement'by' a side of"block"6 and is'adapted toridemn the inwardly eextending-edge of "outer rail"29v'as' the piston'ro'd 591's extended ari'd retracted. Leaf spring- 58" 'serves'to main- -*ta'i-n*roller 62 in engagement *with" rail 29.

"To move the sheet carrier 16 'andtheattached sheet-4,

the feeder pawl 61 engages body42'-of* theadjacent-car- :iier16, and 8.5"PiSt01'l rod' 5'9' is forced outwardly'to its "-extended'position, carrier- 1 6 'is' pushed ahead o'f the 'rod along'trackit. "Movement of-'carrier'--16by cyIinder SS restrlts in correspondingmovement' of-the' 'attached" sheet -vents -the'-'sheet carrier 16 from rolling downwardly On track 14 when pistcnrddFQ-is retracted.

Duringretnrn of the'piston rod,- feeder -pawl61 contacts t the following sheet carrier, which has moved -into the original position of the leading carrier, and the pawl is "pivoted downwardly to enable it to =pass *t'herebeneath. *Afier ;pawl- '61 has+passed*beneaLth-the 'followingcarrier and returned 'to' its upright position 'it will -engage "and "move' the following carrierupon forward? movement "of the piston rod 59.

Iti is"desirable that the-piston or the hydraulic cylinder 55 3 be asp ring returned and ma-nual-ly controllable Fby a suitable valve so *that "when thesilo, "after assembly, is backed' down' on track 14- onto t'he "footing 'fi, aswvill be ilhereinafter described; therate ofretradtionof=pistonrod 59Wfll' be slow andsteady -to*c'or'rtrol the-speedot back up.

The turntable 15; *as shown in FigSJ-L6, '7,-and 8, is *disposed orr-zgrade level "several feet above foot'ing 3--serves 'ato support the eoiledsheetsfi as-the=s-ame are being-fed fjaeks.68 a-re engaged. insuitahle vopenings zinflthe. end-lpor- .tions thereof.

,The lower. ends 1of-.-jacks-.'68 rest-on abeaning-tchannel 69 which is supportedeon thew-groundyranda turntable 115 wmayebe. conveniently leveledrby-the threaded adjustment eofiajacksf68.

.aSheets W4, :in coiled .ifctsm, .a re -:maintained :in cproper gposition on; turntable Baby iauplurality'; of; pneumatic intdustnialtiype -wheels 70. :Awmunrbertof.'the tvheeIsWWare irotatablyssecuredi'in .a ;spaced 'relationaon .:the t'circularly 6 spaced'vertical shafts '71 which are attachedj'to plate? andexten'dupwardly therefrom.

Shafts71"withfattachedwheels 70"form 'a ;po'clcet into which the coiled. 's'heets4 are disposed:in=proper;position 'for feedin'gontothe erection fixture '13.

A vertically disposed guide 'roller"72 is rotatably secured to .an outersupportin'g member '21 approximately beneath the'low point .of the"helical;track "'14. "The lower edge of sheet .4 is adapted toJride on guide roller "72 and is supported'by theroller as the. sheet is fed ontov the fixture 13.

As theleading end portion. of the ;uppermost 'of' the sheets '4 is cut on an angle or taperec'l'to enabl'e1'the topedge ofithes'iloi'tolie in .a substantially horizontal plane, a number of temporary sh'eetjhan'g'ers '73.are emplayed. to support the taperedend duringthefirst convolotion, as shown.in"F ig."7. .Hangers 73 serve to interconnect the (sheet carriers "16' with the taperedfportion of sheet '4.

The lower edge portionfofeach sheet 'lrarrger'f73 is provided with'a' series foff'holes which .are aligned with corresponding. holes .in the 'upper' edge "of .thenpperm'ost sheet '4. L'Suitable hooks "'74 are employed to engage correspondingholes in: sheet 4 andhanger 73' to remov- "ib'ly securethe two sheets together.

.The upper edge portion of each. sheet hanger-"73 is provided with .a series of spaced holes which receive "the outer end of studs :45 of carriersIG.

Thesheet .hangers""73 .are .a 'rfigtilar part "of th recjtion equipment carried .by the erection crew. The

hangers 73.are provided with't'he proper curved contour for the silo and each'hanger has at different and varying width .to compensate"for"the varying .widthuoffthe tapered portioncofthe uppermost sheet, "to. which "the hangers are attached.

' Tov begin assembly "of the erection fixture"13.the base ringi? is initially set infpositiononthe annul'affoot- .ingi3 ins'ide'ithe radius on which the anchor'fbrbltsTare located.

iThe vertical supports'll) arejthen attached to the ;'ring "'17 andthe rails 29iandl3'0 .areprope'r'ly secnre'd'to supports"20.

The center post32 and .urnbrellairingi t are :assembled and positioned onth'e ground within footing "3.

. 'The assembly offix'ture "13'is completedbythe-attaehrnent ofthe radial supports 36 "betweenrp'ost 32s and "supp'orts"20.

To begin. erection, the uppermost off'the. metal sheets "'4 ""of the "silo is disposed 'in coiled form on turntable 1'5"within wheels"70. As shown in Eigurelthe 's'il'o'is composed of four sheets 4, each ofwhich is successively p'la'ced ';on.turnta'b'le -1'5 in pr eparati'on forffee'dirrg the same onto the'erection fixturelfi.

.Each of the sheets is 'des'ignedzwith a'thic'kness' to withstand the internalpressureof the silage at thepartichlar position in the silo at whichthe same is 'disposed. "it is contemplated that for a silo having a "diameterof about 'teetthe diameter of the "largest coil will. be

less "than six feet and i "the i'wei ght er the "heaviest coil will be undef'B S'O O pounds.

The sheets are cut to' the proper: angles, provided with the necessary: bolt holes; glass coated andffiredif" desired and wound "'intoa'coil in"t he*'f'actory. The sheets, are

"transported in the coiledform-andlifted onto the turntable 15"bya-suitable-crane.

After the coiled's'heet is-jplaced"on the'turntable the straps'containing the'coilare *cutand the free endof the sheet is drawn manually toward'the-low point of t'he track 14.

Sheet hangers 73 of theproper tapering widflr-arethen secured to the corresponding portion of thetapereddeading end of the sheet 4.

A sheet carrier 16, disengaged from 'tracl-:"14,: is therecarries the: sheet t by inserting tlreerid o'f stud through one of the holes in the upper edge of the hanger. The plunger 43 of the sheet carrier 16 is then manually retracted within body 42 and locked in this position by pin '54. The pair of vertical rollers 49 of carrier 16 are then placed on the outer rail 29 and the inner roller 46 is snapped into position against inner rail 30 by withdrawing pin 54 from recess 53.

The first sheet carrier 16 is manually moved upwardly on track 14 with the coiled sheet 4 being unwound by the movement, and a second carrier 16 is similarly attached to sheet hanger 73 in a spaced relation thereon and mounted on track 14. Additional carriers 16 are mounted on track 14 and the preceding carriers are manually moved upwardly on the track with the bottom edge of sheet 4 riding on guide roller 72, until the first carrier rides past feeding pawl 61 of hydraulic actuator 55. At this point the pawl 61 will engage body 42 of the first carrier 16 and the sheets may then be moved upwardly on track 14 by means of the hydraulic cylinder 55.

As the sheet 4 and attached hangers 73 are moved upwardly on track 14 by cylinder 55 in a manner previously described, additional carriers 16 are continually attached to the following hangers 73 at the low point of the track.

At about the position of the first convolution, that is, when the first carrier 16 reaches the uppermost point of the track 14, the portion of sheet 4 approaching the lowermost point of the track will be of suflicient width to enable the carrier 16 to be attached directly to the sheet without the use of hangers 73.

After the first convolution is completed the first carrier 16 is withdrawn from the high point of track 14, disengaged from hanger 73 and reinserted at the low point of the track. This operation of removing carriers from the high point and reinserting at the low point is repeated until the entire silo is completed.

To reinsert the carriers 16 at the low point of the track, the outer end of stud 45 is initially inserted through a bolt hole adjacent the lower edge of the first convolution and the carrier 16 is then mounted on track 14. As the unwound portion of sheet 4 moves into a tangential relation with the first convolution the stud 45 is inserted through an aligned bolt hole in the upper overlapping edge portion of the sheet. Thus the second convolution will be disposed with its upper edge portion in overlapping relation with the lower edge portion of the first convolution and this overlapping arrangement is repeated throughout the structure so that each convolution will be outwardly offset from the preceding convolution and there will be no protruding ledges or ridges on the inner surface of the silo to obstruct the downward movement of the silage.

The bolt holes in the upper edge of each sheet 4 are spaced slightly farther apart than the holes in the lower edge portion thereof to compensate for the overlap of convolutions. In addition the spacing of the holes adjacent the upper edge of sheets 4 is varied to compensate for the different thickness of sheets 4.

As the unwound sheet comes into tangential relation with the first convolution and studs 45 of carrier 16 are inserted through aligned bolt holes, suitable smooth head glass-coated bolts are inserted through succeeding aligned bolt holes, not used for studs 45, in the lower edge of the first convolution and the upper edge of the sheet. Bolt holders may be employed to hold the bolts while the same are threaded down by suitable nuts on the outer surface to secure the respective edges together.

Thus as the sheet moves into tangential overlapping relation with the preceding convolution the bolts are inserted and tightened down to progressively secure the respective convolutions together.

If the silo is to contain silage which may emit juices it may be desirable to manually coat the helical and vertical edge portions of sheets 4 to be secured together with a mastic or other sealing compound. The mastic may V be applied to the freelowcr edge portion of each convolution as the same moves beneath track 14 suspended from the carriers 16.

The wound and bolted convolution continues to move upwarddly from the high point of the track as the feeding of sheet 4 onto fixture 13 continues. However, the completed convolution is then unsupported by any portion of the fixture 13.

After about two convolutions of the silo 1 have been completed, the top edge of the completed portion of the silo is in position for attachment with roof member 2.

To accomplish the attachment of roof member 2 a number of pie-shaped roof segments 75 having downwardly flanged outer extremities are disposed on umbrella ring 34 with the flanged extremities of the segments overlapping body portion of silo 1. Each segment 75 is then bolted to the body portion and a circular cap 76 is bolted to the inner extremities of the segments at the center of the silo. The attachment of the roof 2 is completed by securing a number of sealing strips 77 over the radial seams between adjacent segments 75.

After the attachment of roof 2, the feeding of the sheets and bolting of the completed convolutions is continued until the uppermost sheet has been completely fed into the fixture 13. At this time the second coiled sheet is placed on the turntable, unstrapped and manually fed to the low point of the track 14.

Sheet carriers 16 are engaged with the bolt holes in the upper edges of the second sheet and the sheet positioned so that its leading end is lapped over the trailing end of the first sheet to form a vertical joint therebetween. Bolts are then inserted through aligned holes in the lapped vertical ends and threaded down on the exterior of the silo by suitable nuts.

The second sheet is then wound into helical convolutions and the remaining sheets 4 are thereafter successively put on the turntable 15 and also wound about fixture 13 in the manner described above.

After the final sheet 4 has been wound into helical convolutions and bolted together to complete the body portion of the silo, the turntable 15 and any other external structure is disengaged from the fixture 13 and removed from the vicinity of the completed silo in preparation for backing the silo down onto the footing 3 which is several feet beneath the lower circular edge of the silo at the completion of erection.

The backing down is accomplished by manually disengaging the holding pawl 63 which normally engages the rear side of a sheet carrier body 42. The carriers 16 will then move downwardly on track 14 by gravity and the attached silo will correspondingly move downwardly in a helical or spiral manner. To control the speed of back-down the hydraulic cylinder 55 is moved to its extended position with feeding pawl 61 engaging carrier body 42 to remove the weight from holding pawl 63. The holding pawl 63 is then manually released. The carrier body 42 which bears on feeding pawl 61 will move downwardly with the pawl 61 as the piston rod 59 is retracted. It is desirable that the speed of retraction of piston rod 59 be variable so that the speed of backdown can be varied to allow for safe operation under all conditions.

About the time rod 59 has returned to its retracted position the next carrier 16 above has come into engagement with holding pawl 63 and the downward movement of the silo is halted until the rod 59 is again extended and feeding pawl 61 is brought into engagement with the held carrier to take the weight off holding pawl 63. The

holding pawl 63 is then manually released and the silo again moves downward with pawl 61.

During the backdown operation the sheet carriers are progressively disengaged from the silo at the low point of the track 14 and reinserted into the bolt holes in the silo at the high point of the track until the silo has completed its downward movement and is in contacting relation with footing 3. At this time all the sheet carriers -16. are disengaged from f'the; silo and bolts are inserted through ft'he aligned fholesffrom \i'flii'ch'fthe. stridsilS were removed .to completed Rhe bolted attachment .of the I The silo .1 is lthenfleveled onffooting." 3 "and clamped thereto by .clamps "1'5.

,Afterzlthe .silo has beemhacked down ontollfooting 13 and .clampedihereto, the manwayiilOis. cut'into 'thesilo b y.,any .siiitable meansat apposition slightly aboveiheifin- .is'hed gnadellevel. ,Thenerectionfixture 13fis.then -dis-' ..assembled -and .the variougparts arehremovedtfromnthe interiors of. .the-silo. Ithrough manwayll).

:As =the..fixture v 13 .-.is ..enco'rppassed by .the ...completed .silo, it.-is..desirable. to construct each .of. vthetelemen'tsof the-fixture 43,1. such was ventical supports .20,..center post .32.tand,,radial..isuppo.rts;.36, '.-of-. a number: .of..small pieces or sections so that the fixture may be readily dismantled after erection of the-silo and withdrawn fromthe same throughfthw manway 10. In addition, "as the erecting equipment is :toi-bentitilizdeat ivaitiousxlocations in the .field for .theerection of. helical silosmfthe typesdescribed, .it';is essential-that the equipment'bewofia small, :compact, .l-iig'htweig'ht; nature which may bevconvenient lynhandled, ;-paek e'd .and assembled.

With the erection fixture 13 removed from the' interior of the silo, the sections of the unloader track 8, trough 9 and skirt ring 11 are passed through manway and assembled in proper position within the silo. The concrete supporting wall 12 is then poured.

To complete the structure the excavated earth is back filled around the exterior of the silo to grade level and within the central interior of the silo to the level of the track 8 and trough 9. If desired a concrete or metal floor may then be installed in the silo.

It is to be understood that the present invention is not limited to the erection of a silo or storage vessel from glass coated metal sheets, but instead the sheets may be composed of any material having the ability to be wound in coiled form and the strength, when helically wound into the shape of a vessel, to withstand the pressures of the contained material.

Various embodiments of the invention may be employed within the scope of the following claims.

I claim:

1. An apparatus for erecting the cylindrical body portion of a storage vessel from a coiled sheet of material which comprises, a supporting frame, a helical track carried by said supporting frame, sheet carrying means removably secured to the sheet and adapted to ride on said track for progressively unwinding the sheet from the coil and forming the same into a series of helical convolutions with the edge portion of one convolution being secured to the edge portions of the following convolution as each convolution is progressively completed, and means adjacent said supporting frame for rotatably mounting the coiled sheet to enable said sheet to be uncoiled by said sheet carrying means as the samemoves on said track.

2. An apparatus for erecting the cylindrical body portion of a storage vessel from a sheet of material which comprises, a supporting member, a helical track carried by said supporting member, sheet carrying means removably secured to the upper edge portion of said sheet and adapted to ride on said track, and means for moving said carrying means on said track to progressively wind said sheet into a series of helical convolutions with the lower edge of each convolution being attached to the upper edge of the following convolution to provide an integral substantially airtight body portion.

3. An apparatus for erecting the cylindrical body portion of a storage vessel from a sheet of material comprising, a supporting member, a vertically disposed helical track carried by said supporting member and consisting of a single convolution, sheet carrying means removably secured to said sheet and adapted to move upwardly on said track, and means for moving said sheet carrying 10 fimeans's'on' said track 'to' wind 'said 'strip"into a series of helical convolutions with the first formed convolution moving upwardly out -(if "contact- *w'it'hxsai'd track Fas ithe following "convolutions "are. formed, thefirst: convolution :being "secured '-to the secorid convolution as the second 'convolu'ti'on'iis"being formed and eachadditiona'lzconvolu- 'tion' being secured:.to"the precedingi'convolntion*as each additional; convolution "is formed until "the entireibody j portion is constructed.

"4./A11 apparatustor theerection"offiheicylindrical' body portio'mof'a storagevessel adapted torest on'afoundation from sheet material which 'comprisesyaheliciltrak, supporting means *resting on said foundation to carry said track;'sheet'carryingmeans removably secured to thersheet and adapted" to move "on said i'tra'ck, ran'd' means :car'ried "by. said'track' for movingsaid sheet"carryingimeansmpwardly on. said track'pto progressively form' said's'heet 'nto aseriesofihelical convolutions andffor'movingxasai sheet carrying means "downwardly on said track'- aftensa'rdcon- 'volutions'"havebeen securedtitogeither intotheifonnzdfaan integral -=body portion 'to :back said body 3 portion -"down ronto said"fouritlation.

*5. An "apparatus'for asserribling'a storagewesseliihaw "in'g acylindi-ical body'portion' 'formedof'ahelica'lly wound sheet "of material an'da roof member 'to'encloseth'etop of said body portion and a foundation to support said body section, said apparatus comprising, a helical track, supporting means resting on said foundation for carrying said track, a series of sheet winding members removably secured at spaced intervals to the upper edge portion of the sheet and adapted to move upwardly on said track, means for moving said members on said track to progressively form said sheet into a series of helical convolutions with the lower edge of each convolution being secured to the upper edge of the following convolution to provide an integral substantially airtight body portion, means disposed centrally of said body portion and attached to said track supporting means for supporting said roof member, said roof member being secured to the upper end of said body portion, and means for moving said members downwardly on said track after assembly of said body section and said roof to back said body section down onto said foundation. 1

6. A method of erecting the body portion of a storage vessel from a metal sheet comprising, introducing a sheet carrying member onto a helical track, engaging said carrying member with the upper edge portion of said sheet, moving said carrying member upwardly on said track to progressively wind said sheet into a series of helical convolutions, disengaging said carrying member from said sheet, and securing the lower edge portion of each convolution to the upper edge portion of the following convolution to provide an integral substantially airtight body portion.

7. A method of erecting the body portion of a storage vessel from a coiled sheet of metal comprising, mounting said coiled sheet on a rotatable means, engaging a sheet carrying member with the free end of said coiled sheet, introducing said sheet carrying member onto a helical track, moving said carrying member on said track to progressively unwind said sheet from the coil and form said sheet into a series of helical convolutions, disengaging said carrying member from said sheet, and securing the edge portion of each convolution to the adjacent edge portion of the following convolution to provide an integral substantially airtight body portion.

8. A method of erecting a storage vessel adapted to rest on a foundation from a coiled sheet of metal which comprises, introducing a sheet carrier onto the lowermost end of a helical track supported by said foundation, engaging the sheet carrier with the free end of said coiled sheet, moving said sheet carrier upwardly on said track to form said sheet into a helical convolution, removing the carrier from the uppermost end of the track, disengaging said carrier from said sheet, repeating the steps of inserting said carrier at the lowermost end of the track, engaging said carrier with said sheet, moving said carrier upwardly on said track, removing said carrier from the uppermost end of said track until said sheet is formed into aseries of helical convolutions, and securing the lower edge portion of each convolution to the upper edge portion of the following convolution to provide an integralstorage vessel.

9. The method of erecting the body portion of a cylindrical storage vessel from a series of metal coiled sheets which comprises mounting the first of the series of coiled sheets on a rotatable means, engaging a sheet carrying member with the free end of the first coiled sheet, i nserting said sheet carrying member onto a generally helical track, moving said carrying member upwardly on said ,track to progressively unwind said first coiled sheet and form the same into a series of helical convolutions, securing the lower edge portion of each convolution to the upper edge portion of the following convolution to form an integral section of the body portion, mounting a second of the series of coiled sheet on said rotatable means, securing the leading edge portion of said second sheet to the trailing edge portion of said first sheet, engaging a second sheet carrying member to said second sheet, inserting the second sheet carrying member on said track, moving said second sheet carrying member on said track to progressively unwind said second sheet and form the same into a 12 series of helical convolutions, and repeating the aforementioned operations with the remaining coiled sheets until the remaining sheets are wound in a helical manner to complete the cylindrical body portion of the vessel.

10. An apparatus for erecting the helical wound body portion of a storage vessel from a sheet of metal having a tapered leading end portion to permit the upper edge of the completed body portion to lie in a substantially horizontal plane and comprising, a supporting member, a helical track carried by said member, sheet supporting means removably attached to the tapered portion of said sheet, and conveying means removably secured to'said sheet supporting means and adapted to move on said track to progressively wind said sheet into a series of helical convolutions with the lower edge of each convolution being secured to the upper edge of the following convolution to provide an integral substantially airtight body portion.

References Cited in the tile of this patent UNITED STATES PATENTS 1,955,410 Colbie Apr. 17, 1934 2,136,943 Freeze Nov. 15, 1938 2,304,354 Harvey Dec. 8, 1942 2,605,540 Kroll Aug. 5, 1952 

